Seattle-based Amazon has modified its search engine algorithms to effectively favor its private brand products, according to a report in the Wall Street Journal, which cited Amazon employees who worked on the project.

The issue is particularly sensitive because the U.S. and the European Union are examining Amazon’s dual role—as marketplace operator and seller of its own branded products, according to the Wall Street Journal. An algorithm designed toward profitability could steer customers toward thousands of Amazon’s in-house products that deliver higher profit margins for the company than the third-party listings on Amazon’s website.

Although Amazon has publicly refuted the algorithm claims, they have not responded for additional commentary.